The Excel workbook Public-Folder-Migration-Actionplan-EN.xlsx spreadsheet is supposed to support you during a migration of Legacy Public Folders (Exchange Server 2010) to Modern Public Folders in Exchange Online.

The workbook consists of three spreadsheets:

Overview
The spreadsheet "Overview" is used to define the names of the source and target platform. Additionally, you can define the names of the persons or groups responsible for the on-premises and cloud infrastructure. Those names are used in the second spreadsheet. You can define a start date for the migration project. There is no additonal calculation taking place. The date is just referenced in the second spreadsheet. It's up to your creativity to add automatic calculations. Finally, a summary for each available task status (Open, In Progress, Finished) is provided.

Public Folder Migration
The spreadsheet "Public Folder Migration" contains the top down action plan for migration Legacy Public Folders to Modern Public Folders in Exchange Online. The required tasks are grouped and each task can be assigned and the status can be tracked.

Lookup
This spreadsheet is used to provided the task status lookup values.

If you encounter any issues while preparing for migration or during migration of public folder, I recommend to check the Exchange Server Techcommunity Forum.